This invention pertains to a contact lens which is adapted for compensating eye dominance crossover.
The especially adapted contact lens improves visual accuracy in connection with such activities as shooting with a rifle, shotgun, pistol or bowling or looking into the eyepiece of an optical instrument such as a telescope or microscope or a viewfinder.
U.S. Pat. No. 4,761,196 describes a method and means for adapting spectacles for overcoming the adverse affect of the lack of correlation between ones handedness and eye dominance. One common experience wherein the lack of correlation between eye dominance and hand dominance is in shooting. Rifles and shotguns, for example, are designed for use by the majority of the population which has right eye dominance and right handedness. Such shooters can look through the telescope or along the sights of a gun with the right eye while left eye is inactive except to the extent that it contributes to peripheral vision and depth perception. Another person whose left eye is dominant is obliged, by reason of the design of rifles and shotguns for right handedness and right eye dominance, to also site a target with the right eye. To overcome the conflict of the lack of correlation between eye and hand dominance, shooters who have crossover will close their left eye while sighting. This adversely affects their accuracy. The best accuracy by both right and left hand shooters is obtained when the shooter keeps both of his or her eyes open. Closing one eye results in loss of binocular vision, peripheral vision and depth perception. It is especially important for trap shooters to maintain peripheral vision since a shot is fired when the moving clay pigeon or target comes into sight. The image in a microscope, telescope or camera viewfinder is also perceived more closely if the eye opposite the one looking through the eyepiece is kept open.
It has also been established that closing one eye while letting the other do the work has adverse physiological effects. The capillary bed that supplies the retina tissue to which the optic nerve connects is beneath the retina so light does not have to pass through blood. When one eye is closed voluntarily or otherwise for a short time, the brain brings about events that reduce blood flow to both eyes and this reduces visual acuity of the eye that is open and doing the work. This is another good reason for keeping both eyes open when performing visual activities which require accuracy such as shooting or using optical instruments.
A simple test to determine which test is dominant involves holding a finger or a pencil, for example, vertical while the arm is fully extended and with both eyes aligning the pencil with a distant object. Then, the right eye can be closed. If, when the right eye is closed, the pencil appears to shift out of alignment with the distant object, it was the right eye that was doing most of the work all the time and there is right eye dominance. If, when the left eye is closed, the pencil appears to shift out of alignment with the distant object, it is the left eye that is doing most of the work and there is left eye dominance. Before the invention in U.S. Pat. No. 4,761,196 was made for helping those who had to wear eye defect corrective spectacles at least during shooting, the shooters would try to minimize their handicap by putting a black patch or tape over their dominant left eye so they could be more comfortable shooting with a weapon designed for use by the right eye dominant majority. U.S. Pat. No. 4,761,196 provides for adhering a translucent disk to the spectacle lens for the dominant eye while aiming a weapon or viewing through an optical instrument with the other non-dominant eye. The translucent disk is aligned with the pupil of the eye so that no target or image can be seen with the dominant eye but the brain, sensing that both eyes are exposed to light, reacts in such a way that the favorable effects of binocular vision, depth perception and peripheral vision are maintained. The invention disclosed herein provides the same benefits for those who can or do wear contact lenses rather than spectacles.